title: Resonance waveguide reflectors with semi-wide bandwidth at the visible wavelengths.
abstract: We present a resonance waveguide grating with relatively wide bandwidth in the visible region of the spectrum compared to typical resonance structures. The reflective properties of the grating are based on amorphous atomic layer deposited titanium dioxide which has rather high refractive index at the visible wavelengths. The resonance grating provides approximately 20-30 nm bandwidth with over 90% reflectance at the visible wavelengths. The measured reflectances of the fabricated elements show also very good agreement with the theoretical predictions. These kind of reflectors may be useful in applications that make use of LED sources.
authors.affiliation: University of Eastern Finland, Department of Physics and Mathematics, P.O.Box 111, FI-80101 Joensuu, Finland. toni.saastamoinen@uef.fi
authors.forename: Toni
authors.initials: T
authors.lastname: Saastamoinen
authors.forename: Tapani
authors.initials: T
authors.lastname: Alasaarela
authors.forename: Anni
authors.initials: A
authors.lastname: Lehmuskero
authors.forename: Ismo
authors.initials: I
authors.lastname: Vartiainen
authors.forename: Noora
authors.initials: N
authors.lastname: Heikkilä
authors.forename: Markku
authors.initials: M
authors.lastname: Kuittinen
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008027:Light; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation